1. Technical Field
The present invention relates to an Internet Protocol (IP) addressing technique, and more particularly, to a method for looking up an Internet Protocol address using a ternary content addressable memory (CAM).
2. Related Art
Today the Internet is being used by more and more people, and there is an increase in network traffic such as multimedia that requires a broadband connection. In view of these factors, efforts can be taken to attempt to maintain or improve the quality of Internet service.
It would be desirable to improve the efficiency and speed of the process of looking up Internet Protocol addresses. Earlier Internet Protocol address look-up methods can lead to undesirable delays.
Exemplars in the art include Request for Comments (RFC) 1517 entitled Applicability Statement for the Implementation of Classless Inter-Domain Routing (CIDR) and dated September 1993, Request for Comments (RFC) 1518 entitled An Architecture for IP Address Allocation with CIDR and dated September 1993, Request for Comments (RFC) 1519 entitled Classless Inter-Domain Routing (CIDR): an Address Assignment and Aggregation Strategy and dated September 1993, Request for Comments (RFC) 1520 entitled Exchanging Routing Information Across Provider Boundaries in the CIDR Environment and dated September 1993, a publication entitled A Longest Prefix Match Search Engine for Multi-gigabit IP Processing by Kobayashi, M., Murase, T., and Kuriyama, A., in IEEE International Conference on Communications, vol. 3, June 2000, pp. 1360–1364, U.S. Pat. No. 5,920,886 issued to Feldmeier on 6 Jul. 1999 for Accelerated Hierarchical Address Filtering and Translation Using Binary and Ternary CAMS, U.S. Pat. No. 6,081,440 issued to Washburn et al. on 27 Jun. 2000 for Ternary Content Addressable Memory (CAM) Having Fast Insertion and Deletion of Data Values, U.S. Pat. No. 6,237,061 issued to Srinivasan et al. on 22 May 2001 for Method for Longest Prefix Matching in a Content Addressable Memory, U.S. Pat. No. 6,252,872 issued to Tzeng on 26 Jun. 2001 for Data Packet Filter Using Contents Addressable Memory (CAM) and Method, U.S. Pat. No. 6,288,922 issued to Wong et al. on 11 Sep. 2001 for Structure and Method of an Encoded Ternary Content Addressable Memory (CAM) Cell for Low-power Compare Operation, U.S. Pat. No. 6,370,145 issued to Dally et al. on 9 Apr. 2002 for Internet Switch Router, U.S. Pat. No. 6,418,042 issued to Srinivasan et al. on 9 Jul. 2002 for Ternary Content Addressable Memory with Compare Operand Selected According to Mask Value, U.S. Pat. No. 6,401,130 issued to Cain for Auto Aggregation Method for IP Prefix/Length Pairs, U.S. Pat. No. 6,374,326 issued to Kansal et al. for Multiple Bank Cam Architecture and Method for Performing Concurrent Lookup Operations, U.S. Pat. No. 6,052,683 issued to Irwin for Address Lookup in Packet Data Networks, U.S. Pat. No. 6,061,712 issued to Tzeng for Method for IP Routing Table Lookup, U.S. Pat. No. 6,289,414 to Feldmeier et al., entitled PARTIALLY ORDERED CAMS USED IN TERNARY HIERARCHICAL ADDRESS SEARCHING/SORTING, issued on Sep. 11, 2001, and U.S. Pat. No. 6,307,855 to Hariguchi, entitled NETWORK ROUTING TABLE USING CONTENT ADDRESSABLE MEMORY, issued on Oct. 23, 2001.
While these recent efforts provide advantages, they fail to adequately provide an improved method for efficiently and conveniently looking up Internet Protocol addresses.